JP2000160317A - Plasma thermal spraying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma thermal spraying device which is capable of effectively using a flux to improve the thermal spraying efficiency. SOLUTION: A plasma thermal spraying device is provided with an anode 11 having a through hole 11a passing through one end side and the other end side, a cathode 12 which is arranged in the vicinity of one end side of the through hole 11a of the anode 11, a working gas feeding means to feed a working gas 4 to one end side of the through hole 11a of the anode 11, a power source 13 which is connected to the anode 11 and the cathode 12 to generate a plasma arc 5 between the anode 11 and the cathode 12, a guide vane 14 which is provided on an inner circumferential surface of the through hole 11a of the anode 11 to give the spirally whirling flow to a plasma gas 6 circulating in the through hole 11a, and a flux feeding means to feed a flux 2 together with a carrying gas 3 to the plasma gas 6 ejected from the other end side of the through hole 11a of the anode 11, and the staying time of the flux 2 in the plasma gas 6 is increased to surely melt the flux 2 by melting the flux 2 while spirally whirling the flux together with the plasma gas 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a plasma spraying apparatus.

[0002]

2. Description of the Related Art FIG. 4 shows a schematic structure of a conventional plasma spraying apparatus. As shown in FIG. 4, in the vicinity of one end (base end) of the anode 111 having a through hole 111 a penetrating the one end and the other end, a columnar cathode 112 is connected to the through hole 111 a of the anode 111. They are arranged coaxially. Anode 111
And the cathode 112 are connected to a power supply 113. Anode 1
A working gas supply unit (not shown) for supplying a working gas 4 such as an argon gas, a helium gas, or a nitrogen gas is connected to a base end side of the through hole 111a. on the other hand,
In the vicinity of the other end (front end side) of the through hole 111a of the anode 111, a particulate coating material 2 made of ceramic, metal, or the like is provided.
Is connected to the carrier gas 3 such as argon gas in the radial direction of the through-hole 111a.

[0003] The operation of such a plasma spraying apparatus will be described below. The working gas supply means supplies the working gas 4 to the through-hole 111 a of the anode 111 and a power supply 113.
Is operated to apply a voltage between the anode 111 and the cathode 112, and the plasma arc 5 is applied between the electrodes 111 and 112.
Is generated, and the working gas 4 is converted into a high-temperature and high-pressure plasma gas 6.
And squirts from the through hole 111a of the anode 111. At the same time, when the coating material 2 is fed together with the carrier gas 3 toward the plasma gas 6 from the coating material feeding means, the coating material 2 melts while flowing together with the plasma gas 6, and passes through the through-hole 111 a of the anode 111. The thermal spray coating of the coating material 2 is formed on the facing substrate 1 by being applied to the facing substrate 1.

[0004]

The above-described conventional plasma spraying apparatus has the following problems. Since the plasma gas 6 has a high velocity, the residence time of the coating material 2 in the plasma gas 6 is very short.
For this reason, depending on the particle diameter size and the flow rate of the carrier gas 3, the coating material 2 may reach the base material 1 without being partially melted sufficiently. As a result, there was a case where the coating material 2 wasted. A case where a part of the coating material 2 fed from the coating material feeding means passes or is repelled without riding on the flow of the plasma gas 6 depending on the particle diameter size and the flow rate of the carrier gas 3. There is. As a result, there was a case where the coating material 2 wasted.

[0005] In view of the above, an object of the present invention is to provide a plasma spraying apparatus capable of improving the spraying efficiency by effectively using a coating material.

[0006]

According to a first aspect of the present invention, there is provided a plasma spraying apparatus having a through hole penetrating through one end and the other end thereof, and A cathode disposed in the vicinity of one end of the through-hole, a working gas supply means for supplying a working gas to one end of the through-hole of the anode, and the anode connected to the anode and the cathode; A power source for generating a plasma arc between the cathode, a guide vane provided on the inner peripheral surface of the through hole of the anode, and providing a spiral swirling flow to the plasma gas flowing through the through hole; And a coating material feeding means for feeding a coating material to the plasma gas ejected from the other end of the through hole.

A plasma spraying apparatus according to a second aspect of the present invention for solving the above-mentioned problems has an anode having a through hole penetrating one end and the other end, and penetrating one end and the other end. A cathode having a hollow hole, the cathode disposed near one end of the through hole of the anode such that the hollow hole is positioned coaxially with the through hole of the anode, and one end of the through hole of the anode; A working gas supply means for supplying a working gas to a side, a power supply connected to the anode and the cathode to generate a plasma arc between the anode and the cathode, and a coaxial inside the hollow hole of the cathode. A partition tube arranged in such a manner; a coating material feeding means for feeding a coating material to the partition tube; and a heat source for feeding a heat shielding gas between the hollow hole of the cathode and the partition tube. And a shielding gas supply means.

In the plasma spraying apparatus according to a second aspect of the present invention, a guide vane for providing a spiral swirling flow to the plasma gas flowing through the through hole of the anode is provided on an inner peripheral surface of the through hole of the anode. It is characterized by.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a plasma spraying apparatus according to the first invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of a main part thereof, and FIG. 2 is an inner peripheral surface development diagram of the anode.

As shown in FIG. 1, in the vicinity of one end (base end) of an anode 11 having a through hole 11a penetrating through one end and the other end, a columnar cathode 12 penetrates the anode 11. It is arranged coaxially with the hole 11a. Anode 11 and cathode 1
2 is connected to the power supply 13. Through hole 1 of anode 11
A working gas supply means (not shown) for supplying a working gas 4 such as an argon gas, a helium gas, a nitrogen gas, or the like is connected to the base end side of 1a. On the other hand, in the vicinity of the other end (front end side) of the through hole 11a of the anode 11, a particulate coating material 2 made of ceramics, metal, or the like is provided together with a carrier gas 3 such as argon gas in the radial direction of the through hole 11a. (Not shown) is connected. As shown in FIGS. 1 and 2, a guide vane 14 for providing a spiral swirling flow to the plasma gas 6 flowing through the through hole 11 a is provided on the inner peripheral surface of the through hole 11 a of the anode 11.

The operation of such a plasma spraying apparatus will be described below. When the working gas 4 is supplied from the working gas supply means to the through hole 11a of the anode 11 and a voltage is applied between the anode 11 and the cathode 12 by operating the power supply 13, the electrode 11 A plasma arc 5 is generated, and the working gas 4 becomes a high-temperature and high-pressure plasma gas 6 and is ejected along the guide vane 14 from the through hole 11a while spiraling. At the same time, the coating material 2 is transferred from the coating material feeding means together with the carrier gas 3 to the plasma gas 6.
When the coating material 2 is fed toward the substrate 1, the coating material 2 rides on the swirling flow of the plasma gas 6 and spirally melts together with the plasma gas 6 to melt and form the base material 1 facing the through hole 11 a of the anode 11. The thermal spray coating of the coating material 2 can be formed on the substrate 1 by being applied.

That is, the plasma gas 6 is ejected while being spirally swirled by the guide vanes 14,
The coating material 2 is melted while being spirally swirled together with the plasma gas 6.

Therefore, the residence time of the coating material 2 in the plasma gas 6 can be lengthened, and the coating material 2 can be reliably melted and adhered to the substrate 1.

Therefore, according to such a plasma spraying apparatus, since the coating material 2 can be used effectively without wasting, the spraying efficiency of the coating material 2 can be improved.

An embodiment of the plasma spraying apparatus according to the second invention will be described with reference to FIG. FIG. 3 is a schematic diagram showing the extraction of the main parts. However, the same members as those in the above-described embodiment will be denoted by the same reference numerals as those used in the description of the above-described embodiment, and the description thereof will be omitted.

As shown in FIG.
In the vicinity of the base end side of a, a hollow cathode (holo cathode) 22 having a hollow hole 22a penetrating the one end side and the other end side is provided so as to be located coaxially with the through hole 11a of the anode 11. . The anode 11 and the cathode 22 are connected to a power supply 13. A working gas supply means (not shown) for supplying the working gas 4 is connected to the base end side of the through hole 11 a of the anode 11.

On the other hand, in the hollow hole 22a of the cathode 22, a cylindrical partition tube 25 made of an insulating material such as boron nitride is coaxially formed with the hollow hole 22a of the cathode 22. It is arranged so that it may have. One end side (base end side) of the partition tube 25 is connected to a coating material feeding unit (not shown) for feeding the particulate coating material 2 together with the carrier gas 3. One end (base end) of the hollow hole 22a of the cathode 22 is connected to a heat shield gas supply means (not shown) for supplying a heat shield gas 7 such as argon gas having a low thermal conductivity and a high ionization voltage. ing.

That is, the coating material 2 is supplied from the coating material feeding means.
Is supplied together with the carrier gas, the coating material 2
Is supplied to the through hole 11a of the anode 11 through the inside of the heat shield gas supply means.
Is supplied, the heat shielding gas 7 flows between the inner peripheral surface of the hollow hole 22a of the cathode 22 and the outer peripheral surface of the partition tube 25 and is supplied into the through-hole 11a of the anode 11. In other words, The coating material 2 is fed into the through hole 11 a of the anode 11 without being in contact with the cathode 22 while being surrounded by the heat shielding gas 7.

The operation of such a plasma spraying apparatus will be described below. When the working gas 4 is supplied from the working gas supply means to the through hole 11a of the anode 11 and a voltage is applied between the anode 11 and the cathode 22 by operating the power supply 13, the electrode 11 A plasma arc 5 is generated, and the working gas 4 becomes a high-temperature and high-pressure plasma gas 6 and is ejected from the through hole 11 a of the anode 11. At the same time, the heat shield gas 7 is supplied from the heat shield gas supply means to the hollow hole 22 a of the cathode 22 while the coating material 2 is supplied from the cover material supply means together with the carrier gas 3 to the inside of the partition tube 25. When the coating material 2 is fed between the inner peripheral surface and the outer peripheral surface of the partition tube 25, the coating material 2 is supplied to the through hole 11 a of the anode 11 while being protected by the heat shield gas 7, and is supplied to the anode 11 together with the plasma gas 6. The base material 1 is ejected from the through-hole 11a, is heated by the heat of the plasma gas 6 via the heat shield gas 7 and the carrier gas 3 and gradually melts, and faces the through-hole 11a of the anode 11. To form a thermal spray coating of the coating material 2 on the substrate 1.

Therefore, the coating material 2 can be fed in the same direction as the ejection direction of the plasma gas 6, so that the coating material 2 can be surely put on the flow of the plasma gas 6. Since the coating material 2 is supplied into the plasma gas 6 while being surrounded by the heat shield gas 7, the coating material 2 can be prevented from being rapidly heated, and the hollow hole 22 of the cathode 22 can be suppressed.
and the holes 11a and 22a due to the attachment of the coating material 2 to the through holes 11a of the anode 11 and the anode 11 can be reliably prevented.

Therefore, according to such a plasma spraying apparatus, the coating material 2 can be effectively used without wasting as in the case of the above-described embodiment, and the spraying efficiency of the coating material 2 can be improved. Can be improved.

Further, the first invention and the second invention are combined, that is, in the above-described embodiment of the second invention, the guide vane 14 is provided on the inner peripheral surface of the through hole 11a of the anode 11. If provided, the coating material 2 can be more reliably heated and melted. Therefore, even when the coating material 2 having a relatively high melting point and hard to melt is used, the coating material 2 can be effectively used without being wasted. Can be used,
The spraying efficiency of the coating material 2 can be greatly improved.

[0023]

According to the first aspect of the present invention, there is provided a plasma spraying apparatus comprising: an anode having a through hole penetrating one end and the other end; and a cathode disposed near one end of the through hole of the anode. A working gas supply means for supplying a working gas to one end of the through hole of the anode, and a power supply connected to the anode and the cathode to generate a plasma arc between the anode and the cathode. A guide vane provided on the inner peripheral surface of the through hole of the anode, for providing a spiral swirling flow to the plasma gas flowing in the through hole, and the guide vane ejected from the other end side of the through hole of the anode. Since it is provided with a coating material feeding means for feeding the coating material to the plasma gas, the working gas is supplied from the working gas feeding means to the through hole of the anode, and the power source is operated to operate the anode and the cathode. When a voltage is applied between Arc is generated, the working gas becomes high temperature and high pressure of the plasma gas, along a guide vane ejected while rotating from the through hole helically. At the same time, when the coating material is fed from the coating material feeding means to the plasma gas together with the carrier gas, the coating material is melted while spirally swirling with the plasma gas on the swirling flow of the plasma gas. Can be adhered to the base material facing the through hole, and a sprayed coating of the coating material can be formed on the base material. For this reason, the residence time of the coating material in the plasma gas can be lengthened, and the coating material can be reliably melted and adhered to the base material, so that the coating material can be effectively used without being wasted. And the thermal spraying efficiency of the coating material can be improved.

Further, the plasma spraying apparatus according to the second invention has an anode having a through hole penetrating one end and the other end, and a hollow hole penetrating one end and the other end. A cathode disposed near one end of the through hole of the anode so that the hollow hole is positioned coaxially with the through hole of the anode, and a working gas is supplied to one end of the through hole of the anode. A working gas supply means, a power supply connected to the anode and the cathode to generate a plasma arc between the anode and the cathode, and a coaxial power supply disposed in the hollow hole of the cathode. A partition pipe, a coating material feeding means for feeding a coating material to the partition pipe, and a heat shield gas feeding means for feeding a heat shielding gas between the hollow hole of the cathode and the partition pipe. Since it is equipped, it operates from the working gas supply means to the through hole of the anode When a voltage is applied between the anode and the cathode by operating the power supply and a voltage is applied between the anode and the cathode, a plasma arc is generated between the electrodes, and the working gas becomes a high-temperature and high-pressure plasma gas and is ejected from the through hole of the anode. I do. At the same time,
While supplying the coating material into the partition tube from the coating material supply means, the heat shielding gas is supplied from the heat shield gas supply means between the inner peripheral surface of the hollow hole of the cathode and the outer peripheral surface of the partition tube. Then, the coating material is fed to the anode through-hole while being protected by the heat shield gas, is ejected from the anode through-hole together with the plasma gas, and is heated by the heat of the plasma gas via the heat shield gas and the carrier gas. And gradually adhere to the base material facing the through hole of the anode, and a sprayed coating of the coating material can be formed on the base material. Therefore, the coating material can be fed in the same direction as the plasma gas ejection direction, and the coating material can be reliably put on the flow of the plasma gas. To prevent the coating material from being rapidly heated, and to reliably prevent the hole portion from being closed due to the coating material being attached to the hollow hole of the cathode or the through hole of the anode. Therefore, the coating material can be effectively used without wasting, and the spraying efficiency of the coating material can be improved.

In the plasma spraying apparatus according to the second aspect of the present invention, a guide vane for providing a spiral swirling flow to the plasma gas flowing through the through hole of the anode is provided on an inner peripheral surface of the through hole of the anode. Then, the coating material can be heated and melted more reliably, so that even when using a coating material having a relatively high melting point and being hard to melt, it is possible to effectively use the coating material without wasting it. Can,
The spraying efficiency of the coating material can be greatly improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a main part of an embodiment of a plasma spraying apparatus according to a first invention.

FIG. 2 is an inner peripheral surface development view of the anode of FIG.

FIG. 3 is an extraction schematic configuration diagram of a main part of the embodiment of the plasma spraying apparatus according to the second invention.

FIG. 4 is a schematic configuration diagram of a main part of an example of a conventional plasma spraying apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base material 2 Coating material 3 Carrier gas 4 Working gas 5 Plasma arc 6 Plasma gas 7 Heat shield gas 11 Anode 11a Through hole 12 Cathode 13 Power supply 14 Guide vane 22 Cathode 22a Hollow hole 25 Partition tube

Claims (3)

[Claims] An anode having a through-hole penetrating one end and the other end; a cathode disposed near one end of the through-hole of the anode; and a cathode disposed at one end of the through-hole of the anode. A working gas supply means for supplying a working gas; a power supply connected to the anode and the cathode to generate a plasma arc between the anode and the cathode; and an inner peripheral surface of the through hole of the anode. And a guide vane for providing a spiral swirling flow to the plasma gas flowing through the through-hole, and a coating material for feeding a coating material to the plasma gas ejected from the other end of the through-hole of the anode. A plasma spraying apparatus comprising: a feeding unit. 2. An anode having a through hole penetrating one end and the other end, and a hollow hole penetrating one end and the other end, wherein the hollow hole is coaxial with the through hole of the anode. A cathode disposed near one end of the through-hole of the anode so as to be located on the upper side; a working gas supply unit configured to supply a working gas to one end of the through-hole of the anode; A power source connected to the cathode to generate a plasma arc between the anode and the cathode; a partition tube disposed coaxially in the hollow hole of the cathode; and a coating material on the partition tube. A plasma spraying apparatus comprising: a coating material feeding means for feeding; and a heat shielding gas feeding means for feeding a heat shielding gas between the hollow hole of the cathode and the partition tube. . 3. The plasma spraying apparatus according to claim 2, wherein a guide vane for providing a spiral swirling flow to the plasma gas flowing through the through hole of the anode is provided on an inner peripheral surface of the through hole of the anode. A plasma spraying apparatus.